Haplogroups

Dear Group,
My brother recently tested with Nat Geo Geno 2 and his paternal branch is R-Z198.  I've uploaded the info to FTDNA and it displayed R1b11a2a1a  instead of R-Z198.  Where can I find a site that gives equivilants, allowing me to research on other sites using either of these nomenclatures.  I've googled R-Z198 and there appears to be a lot of opinions, controversy, and uncertainty.    Thank you for any help.   Alice